Polyphenylene ether resins are widely used as materials for home appliances, OA devices, office machines, information devices, automobiles, and so forth due to having various properties such as excellent mechanical properties, electrical properties, acid/alkali resistance, and heat resistance, low specific gravity and water absorbency, and good dimensional stability. In recent years, polyphenylene ether resin compositions have also been investigated in relation to applications as reflecting shaped articles for use in projectors, various lighting fixtures, and so forth, and as thin automotive components. Components for use in such applications are required to have thin wall molding fluidity and also, in many cases, long-term thermal stability (heat aging resistance properties) under a certain level of high temperature conditions since these components may be exposed to high temperature over a long time.
However, it is not necessarily the case that polyphenylene ethers innately have adequate thin wall molding fluidity and heat aging resistance properties.
Examples of techniques for enhancing heat aging resistance properties of a polyphenylene ether resin include a technique of using a sulfuric antioxidant and a hindered phenol antioxidant in combination in a specific quantitative ratio (for example, PTL 1). A technique of using an organic sulfuric antioxidant and a specific amine in combination in a specific ratio has also been disclosed (for example, PTL 2).